When the IDF was in control of the South Lebanon security zone, it was customary to talk about a battle of the minds between the Israeli army and Hezbollah. The Shi'ite organization conducted a guerilla war against Israel, with the aim of expelling IDF troops from Lebanese territory (a war which was eventually won when Ehud Barak's government decided to unilaterally withdraw in May 2000).

Throughout its campaign against the IDF, Hezbollah constantly developed new methods of attacking IDF outposts and convoys in the security zone; when the IDF found a defensive - and sometimes offensive - response, the organization answered by changing its tactics. This was a long and tedious game of chess - some would say a game of tag - which usually did not yield clear results.

In many ways, a similar duel is currently taking place between Israel and Hamas on the Gaza border. The regional strategic circumstances, chiefly among them the July military coup in Egypt and Israel's Operation Pillar of Defense a year ago, do not allow Hamas to initiate significant attacks against IDF positions along the Gazan border.

Instead, Hamas is concentrating its efforts on "contingency attacks" - ambitious plans for large terrorist strikes to be carried out once the order is given - in which its tunnel array would play a major part. According to Israeli estimates, Hamas has dug up dozens of tunnels in recent years, some of which already have exit hatches on the Israeli side of the fence. One of the largest of these tunnels was discovered about three weeks ago near Kibbutz Ein Hashlosha.

On Thursday, the IDF carried out an operation on the Palestinian side of the Gazan border, near Ein Hashlosha, to destroy what was left of the tunnel and prevent Hamas from reusing it. However, Hamas was prepared for this, and immediately after the tunnel was exposed it carried out its own detonation which blocked the tunnel and prevented IDF stoops from advancing. In order to demolish the entire route, this obstacle had to be removed.

The IDF's Southern Command and Gaza Division estimated that the location may be booby-trapped, so they opted not to send soldiers inside. Instead, they deployed a drill to dismantle the obstacle.

The drill hit a large underground explosive device, which exploded and injured six soldiers and officers from the entire chain of command involved in the operation: The division's engineering officer (a lieutenant colonel), a company commander and a commander of the tunnels unit.

The decision not to insert soldiers prevented a bigger disaster, but the IDF will have to examine whether there was a way to completely bypass the Hamas ambush. Hamas, it seems, wisely anticipated the Israeli moves.

The IDF retaliated, targeting Hamas members: First, a tank shell killed a member of the organization's armed wing and wounded another. Then, in the early hours of the morning, an IAF jet struck the western entrance shaft to the tunnel, on the outskirts of Khan Yunis. Three key figures in Hamas's tunnel project were killed in the strike, though the IDF said it did not know at the time that they were in the tunnel.

It would not be surprising to see Hamas distribute a video soon, showing the explosion which damaged the drill and injured the IDF soldiers. Yet on the ground, these events hardly spell victory for the organization. Not only has it suffered casualties; more importantly, it seems it will exercise caution in in firing rockets at Israel in response to its losses. In the past, such an incident would have meant an immediate barrage on Sderot, Ashkelon and even Be'er Sheva and Ashdod.

If Hamas continues to refrain from firing rockets, it would be a testament to the restraint forced on the organization's leadership by Egyptian generals, who wish to see the relative peace maintained. From Hamas' point of view, placing the explosive device was not a belligerent act.

Israel operated within the parameter's limits – that narrow 100-meter-strip west of the fence – where the IDF can keep operating, according to agreements made after Pillar of Defense. And yet Hamas had placed explosive devices in order to prevent a further incursion – and that, in the organization's eyes, in a defensive act just like the Israel's actions on the eastern side of the fence, that aim to prevent Palestinian incursion into its territory.

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